Recently, computer programs that can make a perfect or near-perfect copy of commercial copyrighted DVDs have become widely available. These programs, often referred to as “DVD rippers” or “DVD ripping programs”, can either make a decrypted copy of an entire disk onto a recordable DVD, or can copy part or all of the contents of a DVD to a computer hard disk for later viewing or copying to DVD. Many of these DVD ripping programs can be downloaded for free via the Internet.
Ripping programs use a variety of techniques to circumvent the copy-protection mechanisms built into commercial DVDs. Some DVD ripping programs hook themselves into the video driver, or other suitable drivers in the data stream, and copy the content after it has been decrypted by the DVD player application. Other ripping applications can access the media directly from the disk itself, de-crypt it, and copy the decrypted content to a hard drive. Once the decrypted content is stored upon a hard drive, an unlimited number of copied DVDs, or the copyrighted content, can be quickly replicated and distributed in flagrant violation of the rights and interests of the copyright holders.
Thus, these programs are a major concern to the entertainment industry, as they allow the easy creation of perfect digital copies of copyrighted material. In some instances, unauthorized copies of protected media files are outselling legally produced media files. In many instances, media files are being copied and released prior to release of the legally produced media file. As a result, a substantial loss in profits can result from the unauthorized copying and distribution of media files disposed upon DVDs.
One possible way to recognize DVD ripping programs is to maintain a list of known ripping programs that is also known as a “bad boy list.” The bad boy list identifies the ripping programs by their title along with some information about each known ripping program that can be used to recognize it when it is running. Additional program heuristics such as the size and name of the program's executable file, the text in the program's window caption, window class names, etc., can be used by the system to recognize the ripping programs. Upon recognizing that a ripping program is active, the system prevents copying of the media disposed upon the DVD.
The problem with this approach however is that only a limited set of currently-known ripping programs can be recognized. New ripping programs or new versions of existing ripping programs (e.g., foreign language versions of existing ripping programs), are likely to escape detection. As a result, unless a user receives an updated bad boy list (e.g., via an online connection) it is possible that copyright protections can be circumvented. Since it is unlikely that a user who is intentionally violating copyright agreements will allow updating of a bad boy list to occur, the effectiveness of bad boy lists is limited. With the large number of new ripping programs being introduced regularly, relying upon bad boy lists to enforce copyright protection is likely to fail.